Motor fuel and method of manufacture



Patented May 1935 UNITED STATES PATENT OFFICE MOTOR FUEL 'AND METHOD OF MANUFACTURE William Alvah Smith, Hamburg, N. Y.

No Drawing. Application June 24, 1931, Serial No. 546,667

13 Claims.

have or develop on standing a yellow color, and

deposit gum. Off-color gasolines of this char-' acter must be either retreated or sold at a substantial loss in profit. Off-color gasolines almost always give trouble from gum formation and in use such gasolines containing gummy resinous material deposit the gum in the fuel lines, in the carburetor, and on the valves of the engine, thus causing clogging of the fuel supply and sticking of the valves with a consequent reduction in efliciency of engine operation.

An object of the present invention is to provide a process for the treatment of petroleum distillates subject to the defects described above, in which the distillate is treated to reduce its gum-forming tendencies, to bleach it if off-color, and to render it color-stable.

In accordance with this object the invention comprises the steps of forming a composite petroleum oil by adding to the gasoline or other oil or distillate to be treated, a chemical having color bleaching and stabilizing properties, and also gum-inhibiting properties, in amounts adapted to bleach the distillate if ofi-color and to reduce its gum-forming properties and render it stable against discoloration due to standing or to the action of sunlight.

A further object of the invention is the production of a motor fuel composition or other petroleum oil or distillate having minimum gumi'orming characteristics and which is color stable and will remain so under ordinary storage and transportation conditions. a. 1

With these and other objects and features in view, the invention consists in the improved liquid petroleum composition, and process of manufacturing same, hereinafter described and particularly defined in the accompanying claims.

The improved composition of the present invention comprises a mixture of a liquid hydrocarbon oil or distillate of approximately 32 Baum or higher, such as gasoline, and a small proportion of quinhydrone.

The improved process of the present invention in its preferred form comprises subjecting a hydrocarbon oil distillate such as gasoline or kerosene to a preliminary treatment principally to remove hydrogen sulfide, carbon bisulfide and elemental sulfur. To accomplish this the distfllate or gasoline is preferably passed either in vapor or liquid phase in intimate contact with granular caustic for the purpose of removing the sulfur constituentsmentioned above. The distillate is then preferably passed in intimate con-'- tact with the granular copper silicate or'may be otherwise sweetened with sodium plumbite or other sweetening agent. To the sweetened, pretreated distillate is finally added a small propor- 10 tion of the color bleaching and stabilizing agent, quinhydrone. The distfllate treated in this manner will remain color stable for substantial periods of time and moreover if a motor fuel will not deteriorate materiallyin anti-knock value.

The color stabilizer,quinhydrone-acts as a powerful bleaching agent and can be elfectively used for the purpose of improving the color of ofi-color distillate. Furthermore, quinhydrone not only has the property of improving color and 20 rendering distillates color stable, but is also a mild gum inhibiting agent, rendering the distillates treated therewith much more gum stable. For the purpose of securing rapid solution of the quinhydrone in the gasoline or distillate, either or both 25 may be first dissolved in a carrier liquid or intermediate solvent,-for example, suitable amounts of quinhydrone for rendering the distillate color stable, may be firstdissolved in a mixture of equal volumes of a higher alcohol, such as so secondary amyl alcohol and an ester of phthalic acid.- One cc. of a higher alcohol such as secondary amyl plus one half to one cc. of dibutylphthalate or to 1 cc. monochlornaphthalene will dissolve the necessary quantity of quinhy- 35 drone for treating one gallon of gasoline. The amount of. quinhydrone usually used may be placed in solution in the gasoline or oil without the use of an intermediate solvent.

The type or character of the gasoline to be treated has some effect upon the usefulness and quantity of the quinhydrone to be used. For example, some highly unsaturated distlllates' which without a color and gum stabilizer depreciate rapidly both as to color and gum deposi; 45

tion with a consequent reduction in anti-knock value, require the use of larger proportions of quinhydrone than other gasoline. The use of quinhydrone as a color stabilizing agent, according to the process of the present invention, has

shown that gasoline from different sources which have been refined by different refining methods require the addition of varying proportions of quinhydrone to render them color stable. The

proportion of quinhydrone required should in no portions of 0.4 pound per case exceed 5# per 100 barrels of gasoline and in most cases from 1 to 0.03 pound per 100 barrels is sufficient. The usual proportion of quinhydrone added is about 0.4 pound per 100 barrels of gasoline. Normally an ofi-color yellow gasoline is rendered substantially white and color stable by the addition thereto of quinhydrone in the pro- 100 barrels.

While the distillates treated in accordance with the present invention are preferably treated with copper silicate prior to the addition of quinhydrone, nevertheless distillates refined by the usual sulfuric acid-alkali treatment may be effectively used in and benefited by the process of the present invention. For example, a. sulfuric acid refined distillate showing a color of 18 was raised to 22 by the addition of 1 mg. of quinhydrone to cc. of the distillate.

The effectiveness of quinhydrone as a color stabilizing agent may be illustrated by the results obtained in a two months storage test on a cracked copper-silicate-treated gasoline having initially a Saybolt color index of 23 and which was continuously exposed to the light on a milky white glass bench next to an obscure glass window with northern exposure. After standing for two months the quinhydrone-stabilized gasoline sample still had a color index of 23, whereas two checked unstabilized samples had deteriorated in color to a Saybolt index below 20, with a brownish cast.

The use of quinhydrone as a color improving and stabilizing agent not only serves to color stabilize gasolines treated therewith and reduce their gum-forming tendencies, but also permits the use of other'treating steps which leave in the quinhydrone-stabilized gasoline the unsaturated compounds which are largely responsible for the high anti-knock value of the gasoline motor fuel.

Throughout the specification and claims, wherever I have used the word barrel I refer to a barrel of 42 U. S. gallons.

The invention having been thus described, what is claimed as new is:

1. The process of improving the color of cracked gasoline and rendering it color stable, which comprises dissolving therein a small proportion of quinhydrone.

2. A motor fuel mixture comprising a cracked gasoline and a small proportion of quinhydrone.

3. A liquid motor fuel mixture comprising cracked hydrocarbon spirits of the type which tend to deteriorate upon storage and form gum or color, and quinhydrone in the proportions of 100 barrelsof gasoline and between 0.03 and 5 pounds of quinhydrone.

4. A liquid motor fuel mixture comprising cracked hydrocarbon spirits of the type which tend to deteriorate upon storage and form gum or color, and quinhydrone in the proportions of 100 barrels of said gasoline and approximately .4 pound of quinhydrone.

5. A gum inhibitor for liquid fuel compositions comprising quinhydrone in solution in a mixture of a higher alcohol and an ester of phthalic acid.

6. An improved cracked gasoline mixture, stabilized as to color and gum formation by the addition of a small proportion of quinhydrone.

'7. An improved oil comprising cracked hydrocarbon spirits of the type which tend to deten'orate upon storage and form gum or color, and a quantity of quinhydrone in the proportion of not more than approximately five pounds of quinhydrone to each one hundred barrels of said unstable oil.

8. The process of treating a liquid fuel containing cracked hydrocarbon spirits of the type which tend to deteriorate upon storage and form gum or color, which comprises dissolving in said fuel a small proportion of quinhydrone.

9. A liquid fuel composition comprising cracked hydrocarbon spirits of the type which tend to deteriorate upon and stabilized by the addition thereto of a small proportion of quinhydrone. j

10. The process of treating, in liquid form, cracked hydrocarbon spirits of the type which tend to deteriorate upon storage and form gum or color, which comprises dissolving therein sufficient quinhydrone to prevent substantial formation of gum; in said spirits and stabilize the color of said spirits.

11. The process of treating a liquid fuel containing cracked hydrocarbon spirits of the type which tend to deteriorate upon storage and form gum or color, which comprises dissolving in said fuel a quantity of quinhydrone.

12. An improved composition comprising cracked hydrocarbon spirits of the type which tend to deteriorate upon storage and form gum or color, and having gum inhibiting properties and stabilized color, and containing quinhydrone.

13. The process of treating, in liquid form, cracked hydrocarbon spirits of the type which tend to deteriorate upon storage and form gum or color, which comprises dissolving a quantity of quinhydrone in a higher alcohol and an ester of phthalic acid, and adding that solution to said spirits in a quantity sufficient to stabilize said spirits as to gum and color.

WILLIAM ALVAH SIWITH.

storage and form gum or color, 

